1. Field of the Invention
This invention relates to a walking movement aid with a novel structure that enables a safe support of walking by allowing the fall-preventing effect of the user's autonomous reaction, even in the case, for example, of a disturbance on the user, such as an external force in the transverse direction, by supporting the user's muscular strength during the walking, but without excessively restricting the movement of the user who is wearing it.
2. Description of the Related Art
Conventionally, for example as stated in U.S. Publication No. US 2008/0234608 and U.S. Publication No. US 2011/0218466 and the like, a wearable assist device is proposed in order to support walking, etc., of a physically disabled person who has lost muscular strength or an elderly person whose muscular strength has weakened.
Incidentally, the assist device of a conventional structure that was indicated in these US 2008/0234608 and US 2011/0218466 is an external skeleton type assist device, wherein the external skeleton, which is composed of a rigid arm and frame that is worn to fit the user's body, is driven at the joints by motors in order to move the user's legs in combination with the external skeleton's arms.
However, in that type of assist device that employs a rigid external skeleton, if it did not fit the user's physique properly or it was not worn properly, there was a risk of excessive force being applied to the user's joint, etc., during movement.
And, since the rigid external skeleton restricts the movement of the user's joints, there was also the possibility of the fall-preventing effect of the user's autonomous reaction being hindered, and leading to a fall in the case that, for example, there is a disturbance on the user, such as an external force in the transverse direction.
In addition, Japanese Unexamined Patent Publication No. JP-A-2010-042069 proposed assist control which provides sensors that individually measure the ground reaction force that acts on the user's right and left legs and thus detects the load balance at the front-back and left-right of both legs, thereby recovering balance when the front-back or left-right load balance collapsed.
However, with that kind of assist control, a large number of sensors and a system that can control and drive without time lag are required, and it is unavoidable for the structure of the assist device to become quite complicated. Furthermore, since it is necessary to take the user's muscular strength into consideration in cases where the user's muscular strength autonomously responds to a disturbance, it is unavoidable for the driving force control to become even more complicated and difficult. Moreover, since the assist device remains that which employs an external skeleton, it is also unavoidable that there is a possibility that the user's joints may be subject to excessive force that is caused, for example, by a slippage due to a disturbance when the device is worn.